My Doctors have been following a mystery lung mass for 4 yrs, each year I have a CT and no changes. This March I had a MRI because of thorasic pain and of course they studied the previous ct tests and compared what they saw on this MRI, no changes in the mass. Other than I did have multiply cysts in the thorasic area Tarlov cysts. My primary Doc is insisting I still have the yearly CT even tho the MRI was just a couple months ago, he says they the MRI and CT look at diffent things. What possibly? This is actually irritating me, does he get a percentage of ct cost or what? I thought the MRI would show even more depth than a ct. I wish they would actually get to the root of just what it is instead of, artifact, shadow substance nodule looking, all words which have more than one meaning and get on with it. This causes me alot of anxiety of course and this all started in 1996 after I had a large cyst removed from my left breast, then the next year I have a strange mass right under where the cyst was removed, now they are just watching it. Sorry I'm rambling but I'm nervous again. so what would a ct show that a mri wouldn't in this area? Thanks.